PT - JOURNAL ARTICLE
AU - Hicks, Henry
TI - On the Occurrence of Phosphates in the Cambrian Rocks
AID - 10.1144/GSL.JGS.1875.031.01-04.25
DP - 1875 Feb 01
TA - Quarterly Journal of the Geological Society
PG - 368--376
VI - 31
IP - 1-4
4099 - http://jgs.lyellcollection.org/content/31/1-4/368.short
4100 - http://jgs.lyellcollection.org/content/31/1-4/368.full
SO - Quarterly Journal of the Geological Society1875 Feb 01; 31
AB - In a paper by the late Dr. Daubeny, F.R.S., in the Quart. Journ. Chemical Society, vol. vii., entitled “On the produce obtained from Barley sown in rocks of various ages,” he endeavoured to prove, by experiments made with rocks from different parts of the Cambrian strata of North Wales, that there was an almost entire absence of phosphoric acid in the rocks of that age. Having failed to extract any phosphoric acid from these by direct analysis, he adopted the plan of testing the relative capacity of rocks of various ages to yield this ingredient to the crops which grew in them; and by this process he calculated that the Cambrian rocks did not in any case contain more than about part, some containing only . The rock-specimens examined were taken from the slate-quarries near Bangor, the quarries of Llanberis, and from near Dolgelly, probably Lingula-flags. In addition to these, he experimented also with Skiddaw slate from Cumberland, and with micaceous slate from near Glasgow, and from them obtained only much the same proportions. From these results he was led to infer that the seas in which these deposits had accumulated contained little or no animal life, and that we had here approached the borders at least of the lower limit of organic existence, especially as there seemed in addition to be an almost entire absence of lime in any form. In the last edition of ‘Siluria,’ these views are prominently brought forward to prove that very few organic